As you can see in the screenshot. Firesheep gives you a nice list of all user logins you’ve collected, including their profile pictures for your convience; clicking one logins you in to the social network as that user, giving you full access to everything they have access to.

While this type of attack has always been a vague hypothetical possibility and there have always been tools available to take advantage of this sort of exploit, it is has never been this simple. It’s the equivalent of putting a “give me money” button on the side of an ATM. Facebook, Twitter and friends are going to have to take notice.

What Not To Worry About

• Private WiFi. If you know and trust everyone on the WiFi network you’re connected to at home or at work, you probably shouldn’t worry too much. You’re still just as vulnerable to the attack on a private or encrypted WiFi connection. But without open access to the general public, it’s a lot easier to catch the person messing with your account.
• Passwords. This exploit works without ever knowing your password. No respectable website stores your password in plain text and even if someone gets into your account, most websites will not allow a user to change the password without entering the current password.

How To Protect Yourself

Firesheep is taking advantage of the fact that your session data is being sent over wifi in plain unencrypted text. The only effective protection against this is full end-to-end encryption using HTTPS aka SSL. A lot of websites like banks or government services enforce HTTPS connections due to the sensitive nature of the transactions. Most social networks may offer HTTPS if you type it into the address bar (ex. https://facebook.com/ or https://twitter.com/), but since encryption slows down connections somewhat and is a little more taxing on server hardware, no social networks require you to connect with HTTPS. I suspect this will change within the next couple of weeks, if not sooner. In the mean time there are some steps you can take to make your browser use https.

• If you use gmail, they provide a handy setting to force gmail to always use a secure connection. Details here. Enable this if you haven’t already. This is not necessary, gmail went 100% SSL earlier this year.
• For other sites always include the ‘s’ after https when logging on to a website. This should work with any major website. Update your bookmarks now.
• Right now, I’m serious…
• ….
• Unfortunately, updating your bookmarks is not enough. Even when you log in via a secured connection Facebook and many others do not continue to send your traffic over secured links as you click around the site. Meaning, as soon as you leave that first httpS page, your may begin to expose your session details.
• If you use Firefox, Techcrunch has an article on configuring Force-TLS an add-on that forces sites to use HTTPS. Details Here.
• If you use Chrome or Safari, there are a few Greasemonkey extensions you can install that do similar things. This one covers a lot of sites. Take a look at the directory for more.
• Do not user Internet Explorer.

That said…

If you’re wondering who that neighbour with open WiFi has been messaging on Facebook, it’s never been easier to find out. Download the extension (disclaimer: don’t actually do this, it might be illegal).

1. Tools-> Options (Firefox -> preferences or ⌘, on OS X)
2. Select the “Content” tab.
3. Click on the “Advanced” button across from “Enable JavaScript”.
4. Uncheck the “Move or resize existing windows” checkbox.

Thanks to reddit user libertao, another one of the many bits of knowledge I’ve learned from comments on reddit.

Digg Firefox 3 Extension from Kevin Rose on Vimeo.

CSS:

hr {
	background: url("bar.gif") no-repeat;
	width: 385px; height: 15px;
	border: 0;
}

HTML:

<hr noshade="noshade" />

Here’s what it looks like in Firefox 2.

Now Firefox 3.

It would appear that Firefox 3 is adding a border-radius value to all <hr/> tags. Removing the noshade=”noshade” property, or adding -moz-border-radius: 0 in the css will remove the rounded edges.

Check it out.

If you prefer the old style urlbar, you need to install the oldbar extension. https://addons.mozilla.org/en-US/firefox/addon/6227

1. Open about:config (don’t mind the new roadblock)
2. Right-Click the list and create a new boolean ‘extensions.checkCompatibility’, set it to false
3. Restart Firefox

Update: This does not appear to work on the beta 4 release.